Speed up ValueType.Equals

MichalStrehovsky · web-flow · commit 67d96fef950d · 2022-05-25T10:42:19.000+09:00
Inspired by #69723 `SpanHelpers` didn't exist when this part of NativeAOT was written (dotnet/corert#5436 (comment)).
diff --git a/src/coreclr/nativeaot/System.Private.CoreLib/src/System/ValueType.cs b/src/coreclr/nativeaot/System.Private.CoreLib/src/System/ValueType.cs
@@ -64,11 +64,7 @@ public override bool Equals([NotNullWhen(true)] object? obj)
 
                 // Compare the memory
                 int valueTypeSize = (int)this.GetEETypePtr().ValueTypeSize;
-                for (int i = 0; i < valueTypeSize; i++)
-                {
-                    if (Unsafe.Add(ref thisRawData, i) != Unsafe.Add(ref thatRawData, i))
-                        return false;
-                }
+                return SpanHelpers.SequenceEqual(ref thisRawData, ref thatRawData, valueTypeSize);
             }
             else
             {

Original file line number	Diff line number	Diff line change
`@@ -64,11 +64,7 @@ public override bool Equals([NotNullWhen(true)] object? obj)`
`64`	`64`
`65`	`65`	`// Compare the memory`
`66`	`66`	`int valueTypeSize = (int)this.GetEETypePtr().ValueTypeSize;`
`67`		`- for (int i = 0; i < valueTypeSize; i++)`
`68`		`- {`
`69`		`- if (Unsafe.Add(ref thisRawData, i) != Unsafe.Add(ref thatRawData, i))`
`70`		`- return false;`
`71`		`- }`
	`67`	`+ return SpanHelpers.SequenceEqual(ref thisRawData, ref thatRawData, valueTypeSize);`
`72`	`68`	`}`
`73`	`69`	`else`
`74`	`70`	`{`